I. Field of the Invention
The present invention relates to a method for manufacturing a plastic container containing an infusion solution and, more particularly, to a method for manufacturing a plastic container containing an infusion solution which may not allow deterioration of the infusion solution held therein over a long period of time.
II. Description of the Prior Art
In order to prevent infection in hospitals during administration of an infusion solution for injection, closed systems are recently more often used which allow administration of such an infusion solution via a closed system without using an open cannula. A closed system of this type requires a flexible plastic container as a bag for holding an infusion solution in place of the conventional glass bottle or glass ampoule. The closed system utilizes the flexibility of the bag during fluid therapy.
A plastic container containing an infusion solution must be subjected to sterilization before use as must conventional containers. Sterilization is generally performed by autoclaving which is performed in saturated steam at a high temperature. A plastic material which has a low gas permeability at ambient temperature, such as polyvinyl chloride, has a high gas permeability during such autoclaving. Then, oxygen in the atmosphere is introduced into the container through the container wall thereby causing the infusion solution held therein to deteriorate. If the infusion solution contains components which easily deteriorate upon contact with oxygen, that is, if the infusion solution is, for example, a highly concentrated amino acid fluid or fat emulsion, it is subject to deterioration.
Even if the container is sterilized without causing such deterioration in the infusion solution, contamination of the container outer surface during storage may cause a hygiene problem during use.